Mechanism for forming a corner joint flange

ABSTRACT

A method of forming a reinforced sheet metal corner joint wherein a flange is formed across a welded joint in such a way as to gather the metal toward the joint and effectively preclude splitting of the joint in the formation of the reinforcing flange. The metal is gathered toward the welded joint by means of a V-shaped concave die whereby the edge of the metal sheets is progressively turned as the die surfaces move along the metal edge progressively toward the apex of die. The sheet metal is firmly held adjacent the edge by suitable clamp means permitting the edge to be turned by the die into accurate perpendicular relationship to the corner joint.

I v United States Patent 1151 3,659,539 Schnepper [4 May 2, 1972 54] MECHANISM FOR FORMING A 1,915,318 6/1933 Hothersall ..113/120 AA CORNER JOINT FLANGE 1,355,351 10 1920 Norquist ..1 13/ 120 AA 2,350,824 6 1944 R ..1 13 120 A [72] Inventor: Russel F. Schnepper, Boonville, lnd. 0J0 A [73] Assignee: Whirl ool Cor oration Primary ExaminerRichard J. Herbst Attorney-James S. Nettleton, Thomas E. Turcotte, Donald [22] med: 1971 W. Thomas, Gene A. l-leth, Franklin C. Harter, Anthony [21] Appl. No.: 115,272 Niewyk and Robert L. Judd Related US. Application Data Division of Ser. No. 846,194, July 30, 1969, Pat. No. 3,584,371.

References Cited UNITED STATES PATENTS l2/1949 Peterson 11 3/120 AA [57] ABSTRACT A method of forming a reinforced sheet metal corner joint wherein a flange is fonned across a welded joint in such a way as to gather the metal toward the joint and effectively preclude splitting of the joint in the formation of the reinforcing flange. The metal is gathered toward the welded joint by means of a V-shaped concave die whereby the edge of the metal sheets is progressively turned as the die surfaces move along the metal edge progressively toward the apex of die. The sheet metal is firmly held adjacent the edge by suitable clamp means permitting the edge to be turned by the die into accurate perpendicular relationship to the corner joint.

6 Claims, 6 Drawing Figures Patented May 2, 1972 3,659,539

fly

MECHANISM FOR FORMING A CORNER JOINT FLANGE CROSS-REFERENCE TO OTHER APPLICATION This application is a division of my copending application, Ser. No. 846,194, filed July 30, 1969, now US. Pat. No. 3,5 84,371 and discloses and claims only subject matter in said application.

BACKGROUND OF THE INVENTION such as gussets, are conventionally secured to the joint to provide suitable stiffening and reinforcement.

The provision of such gussets is relatively expensive. In replacement thereof, flanges have been formed on the edge of the sheet metal across the welded joint. Such a turned flange provides substantial reinforcement against angular distortion of the corner joint and is relatively inexpensive. However, it has been found that in forming such flanges, the welded seam quite often breaks open, or splits, and thus, rather than a stronger joint, a weaker joint often results.

SUMMARY OF THE INVENTION The present invention comprehends an improved method of forming a reinforced sheet metal joint wherein a flange is turned in the edge of the sheet metal across the joint. The flange is formed by urging the metal of the edge progressively by a concave die so as to gather the metal toward the welded seam joint and thereby not only prevent splitting of the seam but provide a reinforcement of the seam resulting in a strong reinforced welded joint.

The die may define a concave surface made up of two angularly related planar portions engaging the sheet metal at opposite sides of the welded seam. The die is'moved against the sheet metal edge so as to urge the apex of the die toward the welded seam and resultingly bring thedie surfaces progressively closer and closer to the welded seam whereby the sheet metal is gathered toward the seam as discussed above.

The sheet metal may be firmly clamped adjacent the edge being turned so as to provide a rigid support during the flange forming operation and provide a backup means for accurately controlling the arrangement of the flange to be'perpendicular to the longitudinal extent of the welded seam.

BRIEF DESCRIPTION OF THE'DRAWING Other features and advantages of the invention willbe apparent from the following description taken in connection with the accompanying drawing wherein:

FIG. 1 is an isometric view of a refrigerator-freezer appliance with portions broken away to show a reinforced sheet metal corner joint formed by a method embodying the inventron;

FIG. 2 is a fragmentary enlarged'perspective view of the seam welded metal sheets as during a first step in the forming of a reinforcing flange therein;

FIG. 3 is a fragmentary perspective view of the reinforced comer joint;

FIG. 4 is a plan view showing the relationship of the forming die to the partially formed structure of FIG. 2 at the beginning of the step whereby the turned flange arrangement of FIG. 3 is produced;

FIG. 5 is a plan view similar to that of FIG. 4 but with the forming die arranged as upon completion of the turning of the reinforcing flange; and

FIG. 6 is a fragmentary vertical section taken substantially along the line 6-6 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention as disclosed in the drawing, a reinforced sheet metal comer joint generally designated 10 is shown to comprisea pair of metal sheets 11 and 12 jointed along edges 11a and respectively as by seam welding to form a welded joint seam generally designated 13. As best seen in FIG. 2, the sheets 11 and 12 extend substantially perpendicularly to each other whereby the seam 13 defines a right angle turn connecting the two sheets. Illustratively, the comer joint 10 may form a portion of a liner 14 of a refrigeration apparatus illustratively comprising a refrigerator-freezer apparatus.

As indicated above, in such comer joint construction it is desirable to reinforce the joint for improved stiffness and facility of handling as during manufacturing operations including porcelain coating operations and assembly operations. The present invention comprehends forming in the sheets 11 and 12 a turned edge flange generally designated 16 as show in FIG. 3 which extends across the welded seam 13 substantially perpendicularly thereto. As further indicated briefly above, where such reinforcing flanges have been provided heretofore for connection with such sheet metal comers, splitting of the welded seam l3 often occurs thereby preventing any reinforcement of the corner joint and, in fact, weakening the joint. The present invention comprehends forming the flange 16 by means of an improved die 17 which is arranged to wipe across the edge of the sheets 11 and 12 extending across the corner joint in such a way as to gather the metal toward the seam 13 and thereby effectively preclude splitting of the seam.

In forming the comer joint 10 a turned flange portion 11b and a turned flange portion 12b are formed on the sheets 11 and 12 respectively equally oppositely spaced from the seam 13 as best seen in FIG. 2. As shown the flange portions 11b and 12b may extend substantially perpendicularly to the flat planes of sheets 11 and 12. The sheet edge between portions 11b and 12b may be trimmed, or otherwise formed, to define a recessed edge 18 as shown in FIG. 2.

The edge portion of the sheets defined by edge 18 is then turned to define the flange l6 coplanar with flange portions 11b and 12b as shown in FIG. 3. The turning of flange 16 is effected herein by die 17 whichis moved against the edge 18 as illustrated in FIGS. 4 and 5 to progresssively engage a concave surface generally designated 19 with the edge I8so that the portions of surface 19 engaging the edge progressively approach the apex 20 of the surface 19 as the die 17 moves from right to left as seen in FIGSA and 5. 1n the illustrated embodiment surface 19 includes a pairof planar surface portions 19a and 1% which extend-at an obtuse angle to each other to define a V-shaped surface 19. As shown in FIG. 4, the flat planes of sheets 11 and 12 may be substantially perpendicular to each other. As the die l7 moves against edge 18 the flange 16 is formed bythe turning over of the sheet metal between flange portions 11b and 12b. During this forming operation the sheet portions '11 and 12 may be clamped securely by a pair of clamp blocks2l and 22. Clamp block 21 further effectively defines a backup support for the flange 16 limiting the turning thereof to a disposition substantially perpendicular to the seam 13 as shown in'FIG. 6. The die wipes across the upper turned'surface of flange 16 to accurately complete the formation of the corner flange.

The angular relationship of the die surfaces 19a and 19b to the edge 18 as the die moves toward the seam 13 assures that the metal of flange 16 is prevented from pulling apart at the weldedseamlS. It has been found that the movement of the die surfaces may in fact strengthen the seam 13 by gathering the metal at the joint so that an improved reinforced corner joint is obtained.

Upon completion of the formation of flange 16 the corner joint isseparated from the clamps 21 and 22 and the die 17 by 'the simple withdrawal of these elements.

Thus, the liner 14 is provided with improved reinforced comer portions permitting facilitated handling thereof in subsequently manufacturing operations. The formation of the reinforcing flange is extremely simple and economical while yet providing the highly desirable features discussed above.

The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

1 claim: 1. Means for forming a corner flange on a welded sheet metal comer joint, comprising:

means for supporting the comer joint adjacent an end edge thereof; I

a forming die having a concave forming surface symmetrical about a centerline movably disposed with said formingsurface opposite the inner surface of said end edge; and

means for urging said forming surface against said end edge inner surface along a path with said centerline intersecting the center of the welded joint at said end edge thereby to turn said end edge by engagement of the die therewith progressively toward said center of the welded joint.

2. The flange forming means of claim 1 wherein said die surface is V-shaped in transverse cross-section.

3. The flange forming means of claim 1 wherein said corner joint comprises a right angle joint and said forming surface comprises a pair of planar surfaces intersecting at an angle of at least approximately 90.

Deal

4. The flange forming means of claim 1 wherein said supporting means includes back-up means for limiting and turning of said end edge by said forming die to a position perpendicularly across said comer joint.

5. The flange forming means of claim 1 wherein said supporting means comprises means for clamping the sheet metal along substantially the entire extent of said end edge.

6. Apparatus for forming a comer flange on a welded sheet metal right angle comer joint, comprising:

support means for supporting the corner joint adjacent an end edge including means clamping the sheet metal along substantially the entire extent of said end edge, and further including back-up means for limiting the turning of said end edge to a perpendicular position across said comer joint; i

a forming die having a forming surface comprising a pair of planar surfaces intersecting symmetrically at the centerline of said forming surface at an angle of at least 90, said forming die being movably disposed with said forming surface opposite the inner surface of said end edge; and

means for urging said forming surface against said end edge inner surface along a path with said centerline intersecting the center of said welded joint at said end edge thereby to turn said end edge to said perpendicular position by engagement of the die therewith progressively toward said center of said welded joint. 

1. Means for forming a corner flange on a welded sheet metal corner joint, comprising: means for supporting the corner joint adjacent an end edge thereof; a forming die having a concave forming surface symmetrical about a centerline movably disposed with said forming surface opposite the inner surface of said end edge; and means for urging said forming surface against said end edge inner surface along a path with said centerline intersecting the center of the welded joint at said end edge thereby to turn said end edge by engagement of the die therewith progressively toward said center of the welded joint.
 2. The flange forming means of claim 1 wherein said die surface is V-shaped in transverse cross-section.
 3. The flange forming means of claim 1 wherein said corner joint comprises a right angle joint and said forming surface comprises a pair of planar surfaces intersecting at an angle of at least approximately 90* .
 4. The flange forming means of claim 1 wherein said supporting means includes back-up means for limiting and turning of said end edge by said forming die to a position perpendicularly across said corner joint.
 5. The flange forming means of claim 1 wherein said supporting means comprises means for clamping the sheet metal along substantially the entire extent of said end edge.
 6. Apparatus for forming a corner flange on a welded sheet metal right angle corner joint, comprising: support means for supporting the corner joint adjacent an end edge including means clamping the sheet metal along substantially the entire extent of said end edge, and further including back-up means for limiting the turning of said end edge to a perpendicular position across said corner joint; a forming die having a forming surface comprising a pair of planar surfaces intersecting symmetrically at the centerline of said forming surface at an angle of at least 90*, said forming die being movably disposed with said forming surface opposite the inner surface of said end edge; and means for urging said forming surface against said end edge inner surface along a path with said centerline intersecting the center of said welded joint at said end edge thereby to turn said end edge to said perpendicular positiOn by engagement of the die therewith progressively toward said center of said welded joint. 